The present invention relates to module sockets and module socket assemblies for interfacing integrated circuits (“ICs”) with electrical systems, and more particularly, to module sockets and module socket assemblies that provide an interchangeable interface to modules of different form factor types.
Module sockets and module socket assemblies adapted to receive ICs are used to provide both a mechanical and electrical interface between an IC and an electrical system. For example, the module socket or module socket assembly may serve as an interface between: an IC and a system board (e.g. a motherboard or daughter board), an IC and a test system (e.g. an electrical test system), or an IC and a burn-in test system (system for stressing ICs at elevated operating conditions). The IC may comprise one or more semiconductor chips that can be mounted on a module or printed circuit board.
Module sockets are designed to accommodate a particular module form factor and are customized to accommodate the device leads of the module, where device leads refer to the electrical input/output (“I/O”) configuration of the module. Some exemplary module form factors include: pin-grid-arrays (“PGA”), land-grid-arrays (“LGA”), ball-grid-arrays (“BGA”), column-grid-arrays (“CGA”) and the like. PGA form factors have device leads of the pin type. LGA form factors have device leads of the pad type. BGA form factors have device leads of the ball type. CGA form factors have device leads of the column type. PGA, LGA, BGA, and CGA device lead types are well known in the industry, and as such, no further description is warranted.
The module socket houses a plurality of electrical contacts for providing an electrical interface between the device leads of the module and the electrical contacts of the electrical system to which the IC is being interfaced. The socket conventionally has an alignment feature for properly positioning the module in the socket. The socket also conventionally has a section for housing electrical contacts and receiving the device leads of the module.
FIG. 1 illustrates an exemplary conventional BGA socket assembly 100. Socket assembly 100 comprises first pin housing die plate 110, second pin housing die plate 120, a plurality of compliant electrical contacts (e.g. pins) such as pin 130, system board 140, and alignment plate 150. BGA module 160 is received by alignment plate 150.
First and second pin housing die plates 110 and 120 have an array of openings for housing the plurality of pins. The openings in first pin housing die plate 110 are aligned with the openings in second pin housing die plate 120 such that the plurality of pins can be received by both die plates. Fasteners (not shown) such as screws can be inserted into multiple fastener openings to attach first pin housing die plate 110 to second pin housing die plate 120.
First pin housing die plate 110 and second pin housing die plate 120 contain (house) the plurality of pins such as pin 130. First pin housing die plate 110 and second pin housing die plate 120 are made from insulative materials to electrically insulate the pins. In addition to housing the pins, first pin housing die plate 110 and second pin housing die plate 120 provide mechanical alignment between the pins and the electrical contacts (e.g. pads) of system board 140.
The pins are made from conductive materials to electrically couple the system board 140 and the IC module 160. One terminal of the pins corresponds to the device leads of module 160 and the other terminal of the pins corresponds to the electrical pads of system board 140. For example, first terminal 162 of pin 130 is adapted to contact a ball-type device lead of module 160 and second terminal 164 of pin 130 is adapted to contact a pad-type device lead of system board 140.
Most conventional sockets comprise a stationary or floating alignment plate such as alignment plate 150 to mechanically align module 160 to the pin array that is housed in die plates 110 and 120. Alignment plate 150 is made from insulative materials to prevent electrical current flow between adjacent module or socket pins. Conventional BGA socket 100 can be used with BGA form factor modules only and cannot accommodate module device lead types other than balls.
FIG. 2 illustrates an exemplary conventional LGA socket assembly 200. Socket assembly 200 comprises first pin housing die plate 210, second pin housing die plate 220, a plurality of compliant pins such as pin 230, system board 240, and alignment plate 250. LGA module 260 is received by alignment plate 250.
First and second pin housing die plates 210 and 220 have an array of openings for housing the plurality of pins. The openings in first pin housing die plate 210 are aligned with the openings in second pin housing die plate 220 such that the plurality of pins can be received by both die plates. Fasteners (not shown) such as screws can be inserted into multiple fastener openings to attach first pin housing die plate 210 to second pin housing die plate 220.
First pin housing die plate 210 and second pin housing die plate 220 house the plurality of pins such as pin 230. First pin housing die plate 210 and second pin housing die plate 220 are made from insulative materials to electrically insulate the pins. In addition to housing the pins, first pin housing die plate 210 and second pin housing die plate 220 provide mechanical alignment between the pins and the pads of system board 240.
The pins are made from conductive materials to electrically couple the system board 240 and the IC module 260. One terminal of the pins corresponds to the device leads of module 260 and the other terminal of the pins corresponds to the electrical pads of system board 240. For example, first terminal 262 of pin 230 is adapted to contact a pad-type device lead of module 260 and second terminal 264 of pin 230 is adapted to contact a pad-type device lead of system board 240.
Conventional module sockets and module socket assemblies such as the kind illustrated in FIG. 1 and FIG. 2 provide only a single, non-interchangeable electrical interface to only one module form factor type. For example, conventional module sockets and module socket assemblies can accommodate only one form factor such as PGA, LGA, BGA, or CGA. Conventional module sockets and module socket assemblies are not interchangeable and cannot accommodate more than one module form factor type. Such non-interchangeable, single form factor sockets and socket assemblies are cost-prohibitive to the development, verification, and qualification of IC designs.
During IC development, verification, and qualification processes, the module to which a particular IC is mounted is often configured in more than one form factor type. For example, an IC may be mounted to a module where the module is of the LGA form factor type. During verification testing and/or qualification, the IC is often exposed to various test, verification, and stress equipment such as electrical test equipment, thermal cycle equipment, burn-in equipment, ESD equipment, and system verification equipment. At some point, the module to which the IC is mounted may change form factor, for example, from LGA to BGA by having solder balls attached to the pad array. Some stages of verification testing and/or qualification may require one type of form factor (e.g. LGA) while others such as system test and final test may require a different form factor (e.g. BGA).
Because conventional module sockets and module socket assemblies are non-interchangeable, and thus can only accommodate one module form factor type, multiple module sockets and module socket assemblies must be designed and procured in order to accommodate various module form factor types as the IC is subjected to development, verification, and qualification. Having to design and procure multiple module sockets and module socket assemblies is cost prohibitive. Additionally, requiring multiple module sockets and module socket assemblies for one IC design requires additional inventory. No satisfactory solution exists today for a module socket and module socket assembly that is capable of accommodating more than one module form factor type.